Lateral migration of fishes and vulnerability of Chacororé Lake, Pantanal of Barão de Melgaço, Mato Grosso States, Brazil

Abstract

Lateral migrations are movements of fish shoals to and from lentic and/or lotic environments, in order to feed, reproduce or seek favorable survival conditions. This study was conducted in the corixo Manoel Isaac, which connects Cuiabá River to Chacororé Lake in the Pantanal of Barão of Melgaço, State of Mato Grosso. Fish were collected in the period of April-December, that included the seasons of receding water, drought and flood aiming to analyze the lateral migration of fish. It was observed that 12 species used the systems during dry and flood seasons, to feed (time of "lufada”) and to spawn (time of "spawning"), respectively. When the water level is higher, the fish pass between the river and the bay. At the beginning of the ebb (April), the catch is high, going up to July, and CPUEs decrease when the drought period begins (July) and there is a rise in the water level of the corixo at the end of September, second elevation in the catch is verified, however, the direction of movement of the majority of the species is in favor of the current, that is, movement of entrance in the bay. It was concluded that the lateral migration of fish between the Chacororé Bay and the Cuiabá River during the study presented tendencies of movement, for the greater catches, during the months of April to June (ebb) with a sense of movement of the bay and during the flood (October to December), the direction of the fish movement is river-bay.